Steam-generator



J. F. OTIS. STEAM GENERATOR. APPLICATION FILED JAN.13, 1917.

' Patented Oct. 12,1920.

UNITED S ATES PATENT OFFICE.

JOHN 1. cans, or oswne nnw YORK.

STEAM-GENERATOR.

Patented Oct. 12, 1920.

Original application filed April 11, 1914, Serial No. 831,137. Dividedand this application filed January 13,

. T all whom it may concern:

. new and useful Improvements in and Relating to Steam-Generators, ofwhich the following is a specification, this application being adivision of my application filed April 11, 1914, Se. No. 831,137, forsteami generators.

This invention relates to certain improvements in steam generators; andthe objects and nature of the invention will be readily understood bythose skilled in the art in p the light of the'following explanation ofthe accompanying drawings illustrating "what I now believe to be thepreferred em bodiments and mechanical expressions of my invention fromamong other formations,.ar-

' rangements and constructions within the spirit and scope of theinvention.

' The object of the invention is to arrange a superheater as close aspossible to the upper surface of the top flue sheet and within the flameissuing from the fire tubes to utilize the otherwise waste heat forsuperheating the steam and to maintain the superheater within a zone ofthe highest possible temperature; and to so form, construct 1 andsupport the superheater as to. gain the greatest possible advantage fromthis high temperature Without obstructing and disturbing the draftthrough and without causing back pressure within said tubes andwithoutexcessive deposits onthesuperheater and sheet and consequentdifficulties; and to so form the superheater both internally. and

' externally as to subdivide and distribute thesteam in amanner to gainthe full advantageof said high temperature in superheating the generatedthereby.

steam and at the same time to produceasuperheaterof extreme simplicityand strength against the expansive forceof'the-steam; 1

"so'formed that it can be locatedclose to the V and the plate isformedwith perforations lVith" these objects in view, the superheater of myinvention isjcharacterized in whole or in part by a casting or otherbody top tubesheet of the boiler without obstructthe draft through thefirew'tub'es and so formed and balanced with respect to a centralvertical bottom steam inlet that the sution to the draft; saidsuperheat'er' embody-- above said flue sheet.

Serial No. 142,215.

ing uniformly spaced and distributed long rounded comparatively smalltube-like members that are exceedingly strong against internal pressureby reason of their rounded formation and that do not obstruct the draftbecause of their small diameter and rounded formation and that areinternally formed to distribute the steam from said inlet in long smalloutgoing streams and correspondng parallel long small return streamslead- 1ng.to asingle central steam outlet, with abrupt transverse edgesexposed to said steam and traversed thereby at the junctions between theoutgoing and return streams of steam. Referring to the accompanyingdrawlugs;-

Figure'l, 1s a vertical section through a.

Fig. 3, is a section on the line'3'3,'

Fig. 2.

In the particular example illustrated, I show part of an upright steamgenerator having upright inclosing shell or wall 2, and horizontal crownor top flue sheet 1, in which the upper'ends of a multiplicity ofvertical fire'tubes 7, are secured and through which they open into thecombustion chamber 7 I These fire tubes extend through the steam .andwater spaces within the boiler shell and attheir lower endsare securedin a suitable bottom head or flue sheet (not shown) and extendtherethrough and open into the fire box or chamber of the boiler tocarry off the burning gases and smoke and'deliver them into thecombustion chamber above flue sheet 1 after subjecting the water andsteamv to the heat These fire tubes pass through aor separator plate 16,spanning the steam space of the boiler a shortdistance below flue sheet1:, and suitably secured toand carried by shell 1 The platelG fits theinner surfaceof shell 2 to preferably" form a steam tight joint,

for the passage of; the fire tubes, the. plate being otherwiseimperforate. The perforae tions closely receive the fire tubes toformrestricted thin spaces between the surfaces of the fire tubes and theedges of the platesurrounding the tubes throughwhich the steam throughthe center of the flue sheet 1,v and this nipple rises from said fluesheet and passes in films. The steam is more or less superheated inpassing through these perforations along the hot surfaces of the steamand moisture is evaporated therefrom. The plate 16 becomes highly heatedand tends to flash water carried by the steam into vapor, andfurthermore, the edges of the plate at the holes therethrough will tendto catch water carried by the steam and separate the same from thesteam.

I provide a combustion or hot gas chamber at the top of the upper fluesheet 1, and into which the flues or tubes 7 will discharge .the hotor-burning products from the combustion chamber. For instance, I show anupwardly extending hood 18 mounted on the I upper end of the boiler andat the upper end having a suitable outlet or discharge 19. I

provide means for passing the steam from 20 the boiler through thecombustion chamber within this hood for the purpose of separating allwater from the steam and thoroughly superheating the .steam before itpasses off to perform its work whether for heating or power purposes. 11

The boiler is provided with a vertical steam outlet pipe or nipple 20opening into the steam space of the boiler approximately .'the passageof steam therefrom.

The superheater preferably consists of several longitudinally elongatedhollow arms or bodies 22, radiating from a common hollow center or hub23, and the interiors of the hub and arms are spanned by animperforatebafliing plate or diaphragm 24 preferably located centrally or midwaybetween the bottom and bottom walls of the arms and hub. The interiorsof the'arms 22 open into the interior of the hub and the arms areotherwise imperforate and the bafiling plate spans the hub dividing theinterior thereof. into a bottom steam. inlet space receiving the steampipe 20 and top steam outlet space receiving outletlpipe 21. The plateextends from the hub longitudinally within the arms but terminates shortof the outer ends of the arms so that each arm has a "longitudinal steampassage leading outwardly from the inlet steam space of the hub to avertical steam port or passage 25 beyond 'intense heat under the hoodthe end of the bafliing plate and at the outer end of the arm, and alongitudinal return steam passage above the baflling plate and from port25 to the upper steam space of the hub.

The steam enters the superheater vertically through pipe 20, andimpinges directly against the baflie plate and is then divided intooutwardly flowing streamsin the several arms and also return flowingstreams in said arms, and is thereby subjected to the and is thoroughlysuperheated.

The surfaces and edges of the bafliing plate will tend to separate allwater from the steam and vaporize and superheat the same. Thesuperheater is arranged directly above the fire tubes within the zoneand influence of the hot burning gases issuing from said tubes and theheat of such combustion'is thus fully utilized in superheating the steamsub-divided as it is within and by the superheater.

The superheater with its baffling plate is preferably cast in one pieceor otherwi formed integral of. suitable'metal.

It is evident that various changes, modi fications and variations mightbe resorted'to without departing from the spirit and scope of myinvention and hence I do not wish to limit myself to the exactdisclosures hereof.

What I claim is I I 1. A superheater constructed for-location close tothe upper surface of the top tube sheet of a vertical fire tube boilerand to be supported from said sheet by a central vertical nipple formingthe steam passage from the boiler to the superheater; saidsuperheaterconsisting of a central hollow hub having horizontally-elongated hollowarms radiating therefrom and opening thereinto and supportedthereby;said arms being uniformly spaced, closed at their outer ends, small indiameter and substantially cylindrical; the hub and arms beinginternally sub-divided into upper and lower Y steam chambers andsmall-elongated passages, the passages of each arm communicating at theouter end of thearm, said hub having a central vertical bottom steam.supply opening and a central vertical top steam outlet openmg. y V

2. A vertical fire-tube boiler having a steam-outlet from its toptube-sheet, and a superheater arranged horizontally over said tubesheetand receiving the steam from 7 said outlet; said superheater composed ofa spider-like hollow body formed to avoid obstructing the draft from thefire tubes, and internally formed tojprovide uniformly distributed smallelongated outgoingsteam passages or the steam received-from said outletand uniformly. distributed small elongated return passages for the steamfrom.

said outgoing passages and having a steam discharge receiving the steamfrom said several return passages. v

3. A superheater having a central vertical bottom steam inlet andacentral vertical top 'steam outlet and embodying uniformly spaced anddistributed tube-like longitudinally-elongated arms internally formed toprovide long small outgoing steam passages for the steam from said inletand corresponding small long return steam passages 10 JOHN F. OTIS.

